Osmium complexes pyridazines

Instead, evidence now favors the intermediacy of the highly organized mono-osmium complex 15. Various factors could contribute to its excellent enantioselectivity, the most important one being the formation of a binding site consisting of the two methoxy quinolines and the pyridazine linker. As confirmed by X-ray analysis and NMR studies [35,36], this pocket adopts a U-shaped conformation and is capable of perfectly binding aromatic substrates such as styrene through attractive interactions with the methoxyquinolines. In contrast, bulky... 

In this section we consider the osmium complexes of the three potentially bifunctional ligands pyrazine (pyz), pyrimidine (pym) and pyridazine (pyd) (Table 8). All form terminal complexes with... 

Pyridazines form complexes with iodine, iodine monochloride, bromine, nickel(II) ethyl xanthate, iron carbonyls, iron carbonyl and triphenylphosphine, boron trihalides, silver salts, mercury(I) salts, iridium and ruthenium salts, chromium carbonyl and transition metals, and pentammine complexes of osmium(II) and osmium(III) (79ACS(A)125). Pyridazine N- oxide and its methyl and phenyl substituted derivatives form copper complexes (78TL1979). 

Salts of [OsL(NH3)5]3+ (L = pyrazine, pyrimidine, pyridazine) can be made by displacement of nitrogen from [Os(N2)(NH3)5]2+9° or from the triflato complex [0s(0S02CF3)(NH3)J]2+ and the ligands.62 Cyclic voltammetry showed reduction to the osmium(II) species, 90 and the surface-enhanced Raman spectra (SERS) of [Os(pyz)(HNH3)5]3+, [Os(pyz)(NH3)5]2+ and of their ammine-d5 derivatives were measured, as were the IR spectra.91... 

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